The objective of this research is to examine the employment consequences of HIV, focusing on the labor market behavior of HIV positive individuals who use and who do not use highly active antiretroviral therapy (HAART). Like all workers, HIV positive individuals leave the state of employment and unemployment for very different reasons. This study examines the causes of job loss and job acquisition, concentrating primarily on the contribution of HAART and secondarily on the effect of mental health and substance abuse problems. This study uses data from the HIV Cost and Services Utilization Study (HCSUS) and employs discrete choice models of analysis. The specific aims of this research are to (1) examine the effect of HAART on the probability of leaving employment, (2) assess the effect of HAART on the probability of leaving unemployment, and (3) identify whether persons dually diagnosed as HIV positive and having mental health and/or substance abuse problems have differential labor market outcomes than those without mental health or substance abuse problems. Understanding the influence of HAART on the labor market behavior of HIV positive individuals is of fundamental significance to pubic sector policymakers as well as employers in all parts of the economy. On an individual level, it is likely that many people with HIV are still denied opportunities in the workplace due to their HIV status. On a national level, if HAART results in better employment outcomes, it is likely that individuals will remain privately insured for a longer period of time and will be less reliant on federal and state programs (SSI, Medicaid, Medicare, etc,). Furthermore, by having a clearer understanding of the employment outcomes of those who are dually diagnosed with HIV and mental health and/or substance abuse problems, this project will provide new information on the effects of recent policy revisions, including employment-based mental health insurance parity mandates.